STUDIES OF VANADYL-LABELED SIDEROPHORES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 铁载体是一种细菌产物，它结合铁并增加细菌铁的运输速度。铁载体功能的结果最好是在低铁介质中观察到，因为生长开始得更快，可能还会增加生长速度。一些铁结合化合物也已知在含有动物或人血清的介质中起作用。 由于这种现象的延伸是在感染期间刺激细菌的生长，铁载体的合成与细菌的毒力有关。铜绿假单胞菌在铁限制条件下产生两种铁载体，即吡咯啉(PVD)和绿脓素(PCH)。硫酸钒，浓度为12 mM。对铜绿假单胞菌PAO1的生长有很强的抑制作用，尤其是在含有不可利用的Fe(III)螯合剂的严重铁限制条件下。为了阐明钒在伴随钒干扰铁摄取的毒力延迟发生中所起的作用，我们在生理条件下对钒铁载体在X和Ka带的螯合物进行了体外研究。钒是一种著名的生物相关EPR活性自旋探针，可以报告铁离子络合物的EPR所不能达到的铁载体动力学，因为铁和铁离子的快速松弛。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Siderophores are bacterial products which bind iron and increase the rate of bacterial iron transport. The results of siderophore function are best observed in low-iron media as a more rapid onset of growth and possibly an increase in growth rate. Some iron-binding compounds are also known to function in media containing animal or human serum. Since an extension of this phenomenon is the stimulation of bacterial growth during infections, siderophore synthesis has been linked to bacterial virulence. Pseudomonas aeruginosa produces two siderophores under iron-limiting conditions, pyoverdine (PVD) and pyochelin (PCH). Vanadyl sulfate, at a concentration of 12 mM. which is well-suited to observation via EPR, strongly inhibited growth of P. aeruginosa PAO1, especially under conditions of severe iron limitation imposed by the presence of non-utilizable Fe(III) chelators. In order to elucidate the role that vanadyl plays in the delayed onset of virulence attendant on vanadyl interference with iron uptake, we are initiating in vitro studies of vanadyl siderophore chelates at X and Ka band under physiological conditions. Vanadyl is a well-known biologically relevant EPR active spin probe and can report on siderophore dynamics when chelated that are inaccessible to EPR of iron siderophore chelates, due to the rapid relaxation of ferrous and ferric ions.